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51.
Samir Hamrit Kamal Djessas Kahina Medjnoun Idris Bouchama Mohammad Alam Saeed 《Ceramics International》2021,47(16):22881-22888
RF-magnetron sputtering has been carried out at room temperature to deposit vanadium-doped zinc oxide (VZO) nanostructured thin films onto flexible PEN substrates. The sputtering targets of compacted VZO nanopowder have been prepared using a rapid and inexpensive Sol-Gel synthesis followed by a supercritical drying process. Structural and morphological study of VZO particles in the targets has been carried out via X-ray diffraction and Transmission Electron Microscopy (TEM). The nanostructured thin films have been characterized to analyze the structural, morphological, electrical and optical properties as a function of vanadium content from 0 to 4 at.%. Structural characterization of VZO thin films revealed that the deposited thin films have been grown preferentially along (002) and exhibit the hexagonal wurtzite structure. The cross-sectional and microstructural analysis performed by Scanning Electron Microscopy (SEM) confirms the columnar growth of nanostructures. The deposited thin films exhibit transparent behavior with transmission >70% in the visible region. It has been observed that nanostructured thin films with vanadium content of 2% have demonstrated the lowest resistivity (6.71 × 10?4 Ω cm) with Hall mobility of 10.62 cm2 V?1 s?1. The deposited vanadium doped nanostructured thin films would have potential applications in electronic and optoelectronic devices. 相似文献
52.
Salami Hamza Onoruoiza Bala Abubakar Sait Sadiq M. Ismail Idris 《The Journal of supercomputing》2021,77(11):13330-13357
The Journal of Supercomputing - The advent of virtualization technology has created a huge potential application for cloud computing. In virtualization, a large hardware resource is often broken... 相似文献
53.
Ahlaam T. Nomaan Anas A. Ahmed Naser M. Ahmed M.I. Idris M.R. Hashim Marzaini Rashid 《Ceramics International》2021,47(9):12397-12409
ZnO quantum dots (QDs) with average particle size of 4.4 nm were prepared using a low temperature processing solvothermal route. ZnO QD based thin films were then prepared from the ZnO QD based solution using spin coating technique and annealed at 250, 350 and 450 °C. The average grain size and energy band gap of ZnO were respectively increased and decreased from 5.5 to 22.9 nm and 3.37 to 3.27 eV upon increasing the annealing temperature up to 450 °C. The photoluminescence analysis showed that the as-coated ZnO film and ZnO film annealed at 250 °C have high density of oxygen vacancies; these defects were reduced upon increasing the temperature to 350 and 450 °C. The photoelectric properties of the films were strongly affected by the grain size and the defects present in the films. The photo-to-dark current ratio (PDCR) was decreased from 3723 to 371%, whereas the responsivity was increased from 1.25 to 218 mA/W with the increase of temperature to 450 °C. As-coated and 250 °C-annealed films exhibited better photoresponse than others in terms of PDCR, rise time and fall time due to their larger surface-to-volume ratio, making them promising candidate as electron transport layer in perovskite solar cells. 相似文献
54.
LB Becker RA Berg PE Pepe AH Idris TP Aufderheide TA Barnes SJ Stratton NC Chandra 《Canadian Metallurgical Quarterly》1997,30(5):654-666
There is growing recognition that race and socioeconomic variables in health research demand greater attention. The investigators compared racial differences in health definition, health value, and health-promoting behavior of 62 pairs (N = 124) of Black and White college women matched on age, body mass index, and socioeconomic status. Both groups of women had similar definitions of health, valued health to the same extent, and reported similar levels of self-actualization, health responsibility, exercise, and stress management. Black women, relative to White women, practiced fewer nutrition behaviors and had less interpersonal support. Interventions to reduce health risk associated with nutrition practices of Black women are warranted and further research is needed to explore the influence of the social structure of educational institutions on interpersonal relationships and other health behaviors. When socioeconomic status is taken into consideration, Black and White college women demonstrated more commonalities in health behavior than differences. 相似文献
55.
Guanine oxidation signal enhancement in single strand DNA with polyacrylonitrile/polyaniline (PAN/PAni) hybrid nanofibers 下载免费PDF全文
Pure polyacrylonitrile (PAN) and polyacrylonitrile/polyaniline (PAN/PAni) hybrid nanofibers (NFs) were produced via electrospinning and used to monitor guanine oxidation in single strand DNA (ssDNA) by electrochemical methods. Two different methodologies were conducted. First, pre‐synthesized PAni was added into electrospinning PAN solution and electrospun into composite PAN/PAni nanofibrous structure on cylindrical pencil graphite (PGE) surface. In the second route, PAN NFs were electrospun on a PGE surfaces and polymerization of PAni was conducted on the surfaces of the as‐spun PAN NFs. NFs were kept at ?18 °C in a refrigerator for several days. ssDNA was immobilized on the prepared NFs and guanine oxidation signals were observed for each system. The results revealed that use of PAN NFs enhanced signal intensity from 0.92 µA (PGE) to 1.04 µA (PAN NFs). Addition of PAni to PAN increased signal intensity to 1.23 µA. When the PAN NF surfaces were coated with PAni, signal enhancement continued to increase up to 4.19 µA for fourth day and decreased again when PAni‐coated NFs were kept at ?18 °C in the refrigerator. Since the prepared system is fast and cheap, it is promising for application in DNA biosensor devices. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45567. 相似文献
56.
Oscillatory structure–property correlation in azelate polyols and thermoplastic polyurethanes 下载免费PDF全文
Tuan Noor Maznee Tuan Ismail Nor Azowa Ibrahim Aisa Sendijarevic Ibrahim Sendijarevic Christi M. Schiffman Seng Soi Hoong Mohd Azmil Mohd Noor Kosheela Devi Poo Palam Shoot Kian Yeong Zainab Idris Emilia Abd. Malek Norhazlin Zainuddin Vahid Sendijarevic 《应用聚合物科学杂志》2018,135(19)
Azelate polyols of 2000 g mol?1 have been successfully prepared via esterification of renewable azelaic acid with linear diols containing different number of CH2 repeating units. Structure–property correlation of the azelate polyols had been evaluated in thermoplastic polyurethanes (TPUs). TPUs based on azelate polyols of longer chained linear diols with >4 CH2 repeat units retained higher degrees of crystallinity associated with the polyol soft segment. The ratio of hydrogen bonded urethane in the hard segment to free urethane phase mixed with the soft segment in the TPUs showed a complex oscillating dependence with increased number of CH2 repeating unit in the linear diols of azelate polyols. Correspondingly, static and dynamic properties of TPUs also showed the oscillatory dependence, whereby dynamic properties maximized with odd number of CH2 repeating unit and material strength maximized with even number of CH2 repeating unit. The results therefore can be used as guide to select appropriate azelate polyols to target specific TPU performance. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46258. 相似文献
57.
Chiou Sheng Chew Norisma Idris Er Fu Loh Wen‐Chi Vivian Wu Yan Piaw Chua Andrew Thomas Bimba 《Journal of Computer Assisted Learning》2019,35(3):435-449
This paper focuses on the design and evaluation of a theory‐based computer‐assisted summary writing learning environment called Summary Writing‐PAL (SW‐PAL). The SW‐PAL was developed based on four aspects: summarizing strategies, learning theories, prior knowledge, and cognitive load. A quasi‐experiment that involved 58 undergraduates majoring in Computer Science was conducted to examine the effectiveness of SW‐PAL in writing summaries. Two intact classes were selected with 28 and 30 students in control and experimental groups, respectively. The conventional teaching approach was employed in the control group, whereas the SW‐PAL was introduced to the experimental group. Pretest and posttest were administrated to both groups. The findings indicated that SW‐PAL improved students' summary writing performance. A significant variance was noted between intrinsic and extraneous cognitive load among students with varying levels of English proficiency in the experimental group, signifying that the SW‐PAL is more suitable for students with lower language proficiency. 相似文献
58.
A very compact ultra‐wideband (UWB) slot antenna with three L‐shaped slots for notched‐band characteristics is presented in this article. The antenna is designed and fabricated using a new stepped slot with different size, integrated in the ground plane, and excited by a 50 Ω microstrip transmission line. The stepped slot is used to minimize the dimensions of the antenna and to achieve an impedance bandwidth between 2.65 and 11.05 GHz with voltage standing wave ratio (VSWR) less than 2. The length of the stepped slot is equal to a quarter wavelength to create a resonance in the desired frequency. Three L‐shaped slots with various sizes are etched in the ground plane to reject three frequency bands in C‐band (3.7‐4.2 GHz), WLAN (5.15‐5.825 GHz), and X‐band (7.25‐7.75 GHz), respectively. The notched‐band frequency can be controlled by changing the length of the L‐shaped slot. The proposed antenna has a very small size (20.25 × 8 × 1.27 mm3) compared with previous works. The measured and simulated results show a good agreement in terms of radiation pattern and impedance matching. 相似文献
59.
Muhammad Hameed Siddiqi Rahman Ali Muhammad Idris Adil Mehmood Khan Eun Soo Kim Min Cheol Whang Sungyoung Lee 《Multimedia Tools and Applications》2016,75(2):935-959
To recognize expressions accurately, facial expression systems require robust feature extraction and feature selection methods. In this paper, a normalized mutual information based feature selection technique is proposed for FER systems. The technique is derived from an existing method, that is, the max-relevance and min-redundancy (mRMR) method. We, however, propose to normalize the mutual information used in this method so that the domination of the relevance or of the redundancy can be eliminated. For feature extraction, curvelet transform is used. After the feature extraction and selection the feature space is reduced by employing linear discriminant analysis (LDA). Finally, hidden Markov model (HMM) is used to recognize the expressions. The proposed FER system (CNF-FER) is validated using four publicly available standard datasets. For each dataset, 10-fold cross validation scheme is utilized. CNF-FER outperformed the existing well-known statistical and state-of-the-art methods by achieving a weighted average recognition rate of 99 % across all the datasets. 相似文献
60.
Ibrahim Nor Hayati Yaakob Bin Che Man Chin Ping Tan Idris Nor Aini 《European Journal of Lipid Science and Technology》2005,107(12):886-895
Soybean oil (SBO) was blended with 10–40% palm kernel olein (PKO) to obtain SBO:PKO blends with different degrees of unsaturation. Oil‐in‐water (O/W) emulsions were then prepared with 70 wt‐% of SBO or SBO:PKO blends and monitored for their chemical destabilization after an accelerated oxidation process up to 12 days at 60 °C. The formation rate of hydroperoxides, as demonstrated by peroxide value (PV) evolution, throughout the oxidation period was relatively high for a fully SBO‐based emulsion as compared to those with PKO incorporation. Fourier transform infrared (FTIR) spectroscopic method was also performed in parallel with PV determination, providing further information on structural changes of the functional groups due to lipid oxidation in the emulsions. By using a partial least square chemometric method, a developed calibration model that was based on the spectral region between 1800 and 1480 cm?1 was shown to be able to predict the PV in oxidized emulsions over the range of 4–45 meq/kg. With a ‘leave‐one‐out’ cross‐validation optimization procedure, the calibration model provides a good coefficient of determination of 0.98 and a root mean standard error of cross‐validation of 2.09. In general, FTIR spectroscopy is a suitable technique to monitor PV in oxidized emulsions. 相似文献